1. Field of the Invention
This invention relates to photosensitive elements. More particularly this invention relates to photosensitive wash-off elements which employ a lesser amount of silver halide than most conventional elements having a silver halide layer containing a crosslinkable photopolymer and optionally a pigment to achieve image density.
2. Description of the Prior Art
A high tinctorial layer of, for example, colloidal silver in conjunction with a layer of photosensitive silver halide to perform image capture is known from Blake U.S. Pat. Nos. 4,029,509 and 4,047,956. The images formed using these inventions depend on the high tinctorial layer for image density, not the silver halide per se. However, these elements still employ considerable silver and the image forming process is difficult to control.
Van Stappen, U.S. Pat. No. 4,254,210 describes the combination of a tonable photopolymer element on one side of the support and a silver halide emulsion layer on the side opposite thereto. Image capture is provided by the silver layer and this image is then used to image the tonable photopolymer layer which provides double the density. This element also uses considerable silver and is designed mainly as an X-Ray element.
None of the aforementioned U.S. Patents teach the use of mixtures of photopolymer and silver halide to obtain a useful photosensitive element. Thus, there is a pressing need for a photosensitive element that can combine the efficiency and speed of a silver halide element with the reasonable cost offered with a photopolymer system.